Magnetic materials have been used for amusement and educational purposes. For example, containers with magnetic materials have been used before to provide interesting designs based on the magnetic properties of the fluid. Magnetic gels have been designed that respond to a magnet, allowing a gel mass to be attracted and moved by a magnet "wand" for purposes of a demonstration. Two patents cover these different types of uses. The first patent is U.S. Pat. No. 3,648,269 entitled "Magnetic Fluid Display Device," incorporated herein by reference for all purposes. The second is U.S. Pat. No. 5,810,640 entitled "Magnetic Gel Toy and Method For Making."
U.S. Pat. No. 3,648,269 discloses a display device that includes an opaque magnetic ferrofluid and a transparent fluid immiscible with the ferrofluid within a sealed display housing. The display housing can be a cylindrical container or a flat, rectangular, "sandwich" type construction that is transparent for viewing. Different types of ferrofluids are disclosed and include water-based ferrofluids, hydrocarbons, fluorocarbons, and the like.
Unfortunately, the different types of ferrofluid materials disclosed in U.S. Pat. No. 3,648,269 suffer from several problems. One such problem is that the ferrofluid wets the surface of the display housing such that spots and smears form on the inside of the housing surface. The spotting mars the view of the display and eventually reduces the amount of free ferrofluid which forms the display. An additional problem is that the ferrofluid may degenerate over time such that its responsiveness to magnetic fields degrades compared to the initial state of relatively fresh ferrofluid. The combination of these two problems severely reduces the shelf-life of the display.
U.S. Pat. No. 5,810,640 discloses magnetic gel materials that are used as toys, play things, and novelties. Magnetic materials are mixed with a play gel that has a soft, thixotropic property to produce a magnetic gel. Using this gel, various types of play applications are possible. These play applications include resilient plastic covered forms, template action figure body forms, flowers, and volcanoes with various shaped openings. A magnetic tool or "wand" is utilized to attract the magnetic gel in a desired direction.
The magnetic gel disclosed in U.S. Pat. No. 5,810,640, suffers some of the same problems above, as well as other problems now presented. For example, by the very nature of the disclosed gel, the magnetic gel is much more viscous than the ferrofluid used in previous applications stated above. As such, the magnetic gel is slow to respond to a magnetic force and is too thick to allow a definition of a magnetic field to be imposed on it. Furthermore, since the gel is exposed to air, it can dry out over time and become hardened to the point of not responding to a magnetic field as intended.
Accordingly, what is needed is a new type of magnetic apparatus which allows free form sculptures or artistic patterns to be generated by magnetic fields. This magnetic apparatus uses a ferrofluid to form the sculpture. The ferrofluid should have a low enough viscosity that it is quickly shaped along the lines of magnetic force applied to it, it does not agglomerate when placed in a container over long periods of time, and it has great longevity and stability over prior systems.